"To lose
one's shit" has a very similar meaning as "to lose
one's mind" Except your mind is brown, ugly,
smelly, often watery, and is being dropped in, and clogging toilets at an alarming rate, as we speak.
To
lose one's shit, can be used in this
case.
Guy: Was Kanye on grass when he wrote "Lift Yourself"?!
Guy 2: Fo' sheezy nigga, he lost his shit.